The latest edition of the Journal of Feline Medicine and Surgery contains an American Association of Feline Practitioners (AAFP) position statement entitled “Impact of lifestyle choice on the companion cat: indoor vs outdoor”. (The document is actually an update of the previous 2007 position statement “Confinement of Owned Indoor Cats“.) It’s an interesting position statement that tries to balance a lot of issues. There are various arguments both ways, involving health, welfare and behavior. Some people vehemently oppose cats being outdoors because of the number of birds and rodents that they kill, or because they can be injured or killed by vehicles and predators. Some think they’re born to roam. However, let’s just focus on the infectious diseases and zoonotic diseases aspects here.
Zoonotic Diseases
This one’s easy. There are lots of potentially zoonotic bacteria and parasites that cats can acquire outside, from hunting birds and rodents, picking up fleas and encountering other animals. These include things like Salmonella, Toxoplasma and Bartonella. Indoor cats are at much lower risk of shedding many of these zoonotic pathogens. They are also less likely to be injured, reducing the chance of wound infections that might be zoonotic.
Keeping cats indoors is one of my standard recommendations when there are high risk people (e.g. people with compromised immune systems) in the house.
Feline Infectious Diseases
This one’s pretty clear too. It’s logical. The fewer individuals a cat (or anyone else) encounters, the lower the disease transmission risk. Cats that get outside have a greater risk of exposure to diseases from other cats (e.g. feline immunodeficiency virus (FIV)), insects (e.g. plague in some regions) and prey (e.g. Salmonella). Outdoor cats also get into more fights and not uncommonly end up with cat bite infections or abscesses. The risks are heightened in cats with compromised immune systems and some other illnesses, just like they are for people with compromised immune systems.
Ultimately, while it’s clear that keeping cats indoors reduces infectious disease risks both for the cats and their human contacts, there’s no simple answer to the indoor vs outdoor question. Some people are adamant that cats should be indoors only. Some are adamant the other way. Both groups have good arguments, but sometimes forget the individual aspect… the cat itself.
Myself, I have both. We have Finnegan, a purely indoor cat. This summer, we also adopted two cats as part of the Guelph Humane Society’s Barn Cat Adoption Program. Those two wouldn’t do well indoors (and Finnegan would probably start peeing everywhere if we tried). They live outside (although one, Rumple, has become more of a deck and garage cat). Yes, it increases their risk of diseases and attacks from coyotes and other animals. Yes, they’ll kill some birds and other wildlife. But for them, it was outdoor living or euthanasia.
It’s a complex situation and I know I’ll get strongly opinionated comments in response to this topic. In my perfect world, all cats would be indoors, but not all cats fit into my perfect world. So, I think the default should be keeping cats indoors whenever possible, both for their health and the health of their families. That’s particularly important when the people or cats are at increased risk of disease. But, some cats won’t do well inside 24/7 and some allowances can be made for them as well, in the right situations.
The indoor/outdoor decision needs to be made based on a large number of factors and there’s no single approach that works for all cats, households and regions.
The position statement can also be found on the AAFP’s website: http://www.catvets.com/guidelines/position-statements/lifestyle-choice-position-statement